The OpenNMS Community makes a few builds of the OpenNMS software platform available at any given time. These builds vary in purpose, from deployment ready to developer specific to those who wish to live on the cutting edge. You'll need to pick from one of the following options:

stable

The latest officially released stable version of OpenNMS. The current stable version is 20.0.1. If you are putting OpenNMS into a production environment for daily use, this is the recommended version to install.

testing

If a new OpenNMS stable release is being prepared, this will contain snapshot builds of that release. Otherwise, it will contain a the latest officially released stable version of OpenNMS.